Prediction of available potassium in Ontario soils by electro-ultrafiltration and chemical extraction

1992 ◽  
Vol 72 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Liangxue Liu ◽  
T. E. Bates ◽  
T. S. Tran

The extractions of soil K by electroultrafiltration (EUF) and by chemical methods were compared as predictors of plant-available K for greenhouse-grown alfalfa on 38 Ontario soils. The relation of soil properties to the amount of K extracted by EUF fractions was also examined. The contents of silt and clay were negatively correlated with EUF-K at 50 V and 22 °C and positively correlated with EUF-K at 400 V and 80 °C. Soil pH and organic matter were not significantly correlated with the amounts of K extracted in the EUF-K fractions. The EUF extraction of K was influenced by the presence of carbonate or high exchangeable calcium in soils. Similar correlations were obtained between K uptake and K extracted by chemical methods and the sum of EUF-K fractions. When used along with other soil properties, EUF-K fractions and K extracted by chemical methods predicted availability of soil K with roughly equal ability. The model using the sum of K extracted by EUF at 50, 200 and 400 V is the simplest one and contains three variables, K, K2 and Ca2. The use of EUF is limited due to cost of equipment and time required for analysis, unless a number of nutrients can be accurately determined on one extract. Among the chemical methods, equations developed using three nonacidic extradants, NaCl, ABDTPA and NH4OAc explained more variation in K uptake than two acidic extractants, Mehlich 3 and 0.1 M HNO3. The NaCl model, ABDTPA model and NH4OAc model contained the same variables and had similar R2 values (0.88–0.91). Key words: Available K, chemical methods, electro-ultrafiltration, EUF-K fractions, K uptake

1987 ◽  
Vol 67 (1) ◽  
pp. 17-31 ◽  
Author(s):  
T. SEN TRAN ◽  
M. TABI ◽  
C. R. DE KIMPE

The objectives of this study were to compare the EUF procedures (50, 200 and 400 V) and some chemical methods (1 N NH4OAc, 0.01 M CaCl2, 1 N HNO3) in order to estimate the K fertility levels of 60 Quebec soils. The EUF-50 V-K quantities corresponded to CaCl2-K while EUF-(50 + 200 + 400 V) to acetate-K. The relations between EUF-(50 V)-K, EUF-(200 V)-K to Acetate-K were improved when introducing clay contents, CEC values and K saturation levels. On the other hand, soil pH, carbonate and exchangeable (Ca+Mg) contents had significant effects on the relations between EUF-400 V-K and Acetate-K. A greenhouse experiment, using ryegrass as the test plant, was carried out on these soils with two treatments (complete fertilization with and without K). EUF-400 V-K, Acetate-K and EUF-(50 + 200 + 400 V)-K were the best criteria to estimate relative yields and K uptake by the plant. EUF-(50 + 200 V) underestimates K fertility level for soils rich in clay, having high pH (H2O) or exchangeable (Ca+Mg) contents. Higher correlation coefficients for K uptake by the plant were obtained in multiple regression where EUF-(50 + 200 V)-K and EUF-400 V-K were taken into account. The relation between plant K uptake and K values determined by all methods were improved by considering the K saturation levels on cation exchange sites. Acetate-K contents explained up to 88% of the variation in K uptake when K saturation level was introduced. Finally, this method can overestimate the K fertility levels for soils rich in clay or organic matter. Key words: Electro-ultrafiltration, available K, soil properties, exchangeable K


1985 ◽  
Vol 65 (1) ◽  
pp. 25-34 ◽  
Author(s):  
W. VAN LIEROP ◽  
T. SEN TRAN

The objective of this study was to compare extractable potassium levels removed from soils by electro-ultrafiltration (EUF) and by conventional chemical soil tests. Accordingly, concentrations of potassium removed from soils by three EUF and six chemical extraction procedures were compared, on a group of 50 soils which contained less than 20% clay and on a second group of 52 soils which contained from 20 to 50% clay, by means of regression and correlation techniques. The following three EUF extraction procedures were tested: (i) 50 V at 5-min; (ii) 50 V at 5-min plus 200 V at 25-min; and (iii) 300 V at 15-min. Results indicated that the concentrations of soil K found in the combined anolyte and catholyte of the EUF or removed by the chemical procedures were very closely related (r-values generally greater than 0.90). However, EUF was less efficient in removing K from soils containing higher proportions of clay than NH4OAc, the new Mehlich solution, or the double acid mixture used at 1:30 wt/vol soil-solution ratio. As soil K fractions extracted by different EUF procedures were closely related among themselves as well as between the chemical methods tested, EUF would not provide soil fertility information that could not be obtained by less laborious and expensive chemical procedures. Key words: Soil testing, NH4OAc, double acid, new Mehlich extractant, electro-ultrafiltration


2020 ◽  
Vol 5 (2) ◽  
pp. 65-71
Author(s):  
Israt Jahan ◽  
AKM Abul Ahsan ◽  
MMR Jahangir ◽  
Mahmud Hossain ◽  
Md Anwarul Abedin

Soil physico-chemical properties are an important phenomenon for sustainable crop production and maintenance of optimum soil health. Hence, a laboratory measurement was conducted with soil samples of three years long experimental field of the Department of Soil Science, Bangladesh Agricultural University, Mymensingh to assess the changes in five selected soil physico-chemical properties viz. soil texture, bulk density, soil pH, total nitrogen and organic matter. The experiment was laid out in a split plot design with two water regimes (continuous flooding and alternate wetting & drying) in the main plots and five fertilizer treatments (N0 - control, N1- 140 kg N/ha as PU, N2- 104 kg N/ha as USG (2× 1.8 g/ 4 hills), N3 - 5 t CD + PU @ 140 kg N /ha on IPNS basis and N4- 5 t CD + USG (2× 1.8 g/ 4 hills @ 104 kg N/ha)) in the subplots under rice-rice cropping pattern with three replications. After three years, soil samples were collected at 0-5 and 5-10 cm soil depths for measuring bulk density and at 0-10 cm depth for other soil properties and analyzed. Results found that % sand, % silt, % clay, bulk density and soil pH was not changed significantly compared to initial status. Percentage of total nitrogen and organic matter was significantly affected by irrigation and fertilization. Total nitrogen (%) was higher in AWD whereas organic matter (%) was higher in CF practice. The highest total nitrogen (%) and organic matter (%) was found in N4 treatment in which USG was applied in combination with cowdung as organic manure. It can be suggested that N4 treatment was formed good combination for sustaining chemical properties of soil. Further long- term experimentation will be needed to know the changes in soil properties for sustainable crop production and improving soil health. Asian Australas. J. Biosci. Biotechnol. 2020, 5 (2), 65-71


2013 ◽  
Vol 27 (1) ◽  
pp. 57-67 ◽  
Author(s):  
S.E. Obalum ◽  
J. Oppong ◽  
C.A. Igwe ◽  
Y. Watanabe ◽  
M.E. Obi

Abstract The spatial variability of some physicochemical properties of topsoils/subsoils under secondary forest, grassland fallow, and bare-soil fallow of three locations was evaluated. The data were analyzed and described using classical statistical parameters. Based on the coefficient of variation, bulk density, total porosity, 60-cm-tension moisture content, and soil pH were of low variability. Coarse and fine sand were of moderate variability. Highly variable soil properties included silt, clay, macroporosity, saturated hydraulic conductivity, organic matter concentration, and cation exchange capacity. Overall, soil pH and silt varied the least and the most, respectively. Relative weighting showed that location dominantly influenced the soil variability, except for soil porosity and organic matter concentration influenced mostly by land use. Most of the soil data were normally distributed; others were positively skewed and/or kurtotic. The minimum number of samples (at 25 samples ha-1) required to estimate mean values of soil properties was highly soil property-specific, ranging from 1 (topsoil pH-H2O) to 246 (topsoil silt). Cation exchange capacity of subsoils related fairly strongly with cation exchange capacity of topsoils (R2 = 0.63). Spatial variability data can be used to extrapolate dynamic soil properties across a derived-savanna landscape.


2020 ◽  
Vol 30 (3) ◽  
pp. 282-287
Author(s):  
U Kumar ◽  
H Rashid ◽  
NH Tithi ◽  
MY Mia

The study was intended to investigate the status of soil properties and its relation to soil pH in Madhupur tract soil of Tangail district, Bangladesh. Thirty soil samples were collected during the period from June-July, 2016 covering four types of land as high land, medium high land, medium low land and low land. The interpretative data showed that the range of pH was strongly acidic to slightly acidic (5.27- 5.90), mean pH was slightly acidic (5.61). The organic matter (OM) status was medium (2.11 to 2.33 %) and mean OM was medium (2.24 %). The Nitrogen (N) status was low (0.11 to 0.13 %) and mean N status was medium (0.12 %). The range of the Phosphorus (P) status was found very low to medium (1.63 to 11.06 µg g-1 soil) and mean P status was medium (7.37 µg g-1 soil). The Potassium (K) status was low to very high (0.15 to 0.75meq/100 g soil) and mean K status was low (0.18 meq/100 g soil). The range of the Sulfur (S) status was found from low to medium (11.73 to 16.31 µg g-1 soil), mean S status was low (13.26 µg g-1 soil). The range of the Zinc (Zn) status was found from medium to high (0.96 to 2.23 µg g-1 soil), mean Zn status was optimum (1.55 µg g-1 soil). The range of the Boron (B) status was found from medium to very high (0.39 to 0.86 µg g-1 soil), mean B status was high (0.73 µg g-1 soil). The Calcium (Ca) status was medium to optimum (4.42 to 5.23meq/100 g soil), mean Ca status was optimum (4.83 meq/100 g soil). The Magnesium (Mg) status was optimum to high (1.21 to 1.75meq/100 g soil), mean Mg status was optimum (1.37 meq/100 g soil). No significant correlation of OM and other nutrients with pH. Progressive Agriculture 30 (3): 282-287, 2019


Author(s):  
Tianfu Han ◽  
Dongchu Li ◽  
Kailou Liu ◽  
Jing Huang ◽  
Lu Zhang ◽  
...  

Soil acidification is one of the major soil degradation phenomenon in tropical and subtropical region, which cause reductions in soil fertility, particularly potassium (K), and declines in crop yield. However, it remains unclear whether and how the status of K in soils and crops changes with the application of lime to alleviate soil acidification. Six treatments of long-term experiments (started 1990) in subtropical region were carried out. Regardless of fertilization regime, lime addition markedly increased grain and straw yields compared to those yields without lime application. Lime addition also led to significant decreases in the apparent K balances compared to soils without lime application. The agronomic K efficiency and partial factor productivity of K fertilizer both significantly increased after lime application. Lime addition reduced the soil exchangeable K (EK) content and stock, while increased soil non-exchangeable K (NEK) content and stock. Redundancy analysis showed that K input, lime, pH, and exchangeable calcium all significantly affected the K in soil and crops. Path analysis showed that lime indirectly influenced soil K (EK and NEK) by directly affecting soil pH, exchangeable calcium, K uptake and apparent K balances. These results suggest that lime addition is a viable strategy for improving crop yields and K fertilizer efficiency in degraded soils caused by acidification. Lime significant increased K uptake which lead to decreased soil EK content and stock. Additional, lime also increased soil NEK content and stock which was regulated by soil pH, exchangeable calcium, and crop growth.


2017 ◽  
Author(s):  
Zainal Muktamar ◽  
Bajora Justisia ◽  
Nanik Setyowati

Compost application to soil leads to the improvement of its properties. However, nutrient content and enhancing capacity of compost are highly dependent on the original source and additive. The purpose of the experiment was to investigate selected soil quality indicators’ improvement and sweet corn growth following application of water hyacinth compost. Greenhouse experiment was carried out using Completely Randomized Design with 2 factors. First factor consisted of soils from humid tropics, i.e. Andepts, Udepts, and Udults and second factor comprised of water hyacinth compost rates, i.e. 0, 5, 10, 15, 20, and 25 Mg ha-1. Treatment combinations were replicated 3 times. Compost was incorporated in soil a week before planting of sweet corn. After reaching maximum sweet corn growth, soil sample was collected, air-dried, grinded and passed through 0.5 mm screen, and analyzed for selected soil properties, except microbial biomass carbon (MBC) and particulate organic matter carbon (POMC) which were analyzed using fresh soil samples. The experiment pointed out that application of water hyacinth compost on Udepts exhibited the highest total soil organic carbon (TSOC), MBC, soil pH and available P (Bray I), followed by those in Andeps and Udults. Particulate organic matter carbon (PMOC), however, was highest in Andepts as compared to other soils. Higher rates of compost application contributed higher increase in TSOC, MBC, soil pH, available P, and exchangeable K. Udults had more pronounced increase in soil pH and decline of exchangeable Al than other soils. Pearson correlation analysis showed that the most distinct correlation among soil properties was observed between exchangeable Al and soil pH, followed by TSOC and MBC with coefficient correlation of -0.91 and 0.85, respectively. Correlation between soil properties and sweet corn growth exhibited that the most prominent correlation was shown between available P and shoot dry weigh of sweet corn with coefficient correlation of 0.92. This indicates that soil available P has significant contribution on sweet corn growth.


Soil Research ◽  
1990 ◽  
Vol 28 (2) ◽  
pp. 259 ◽  
Author(s):  
JO Skjemstad ◽  
HVA Bushby ◽  
RW Hansen

The levels of iron and aluminium extracted from 36 surface soils by pyrophosphate, oxalate and dithionite are compared with a number of other soil properties. Correlations suggest that aluminium released by these extraction procedures is largely associated with organic matter while only a small fraction of the iron released is in this form. Significant correlations between soil pH and the negative logarithms of both oxalate (r = 0.715) and pyrophosphate (r = 0.959) extractable iron in soils with >20% clay content indicate that pH is the most significant factor in determining the level of ferrihydrite and iron/organic matter complexes in surface soils. The significance of these relationships in terms of soil weathering processes is discussed. Further, the data suggest that pyrophosphate extractable iron is a useful indicator of the most active, mobile component of iron in surface soils.


1990 ◽  
Vol 70 (4) ◽  
pp. 607-615 ◽  
Author(s):  
LIANGXUE LIU ◽  
THOMAS E. BATES

The effectiveness of five extractants, NaCl, AB-DTPA, NH4OAc, Mehlich 3 and HNO3 was evaluated on 72 Ontario soils for prediction of plant-available K to alfalfa (Medicago sativa L.) grown in a greenhouse. Total K uptake by four cuts of alfalfa was used to measure plant available soil K. The average amounts of K extracted were in ascending order: AB-DTPA < NaCl < = NH4OAc < Mehlich 3 < HNO3. The highest simple correlation with K uptake by alfalfa was obtained with HNO3 (r = 0.76) and the lowest with NaCl (r2 = 0.61). The K uptake by alfalfa was used as the dependent variable to develop predictive models using stepwise regression, with extractable soil K, exchangeable Mg and Ca, soil pH, organic matter, cation exchange capacity (CEC), and contents of silt and clay as independent variables. The best prediction of K uptake with extracted soil K and its square was AB-DTPA (R2 = 0.84), followed by HNO3 (0.81), NH4OAc (0.81), NaCl (0.78) and Mehlich 3 (0.77). Inclusion of soil properties improved the effectiveness of prediction. The models developed with the different extractants differ in the number of variables which contributed significantly at 5% probability. Based on the final R2 and ease of measurement of variables, the NH4OAc model is one of the best as a predictor of availability of K in Ontario soils when used along with other soil properties such as plant-available nonexchangeable K and soil organic matter. Key words: Potassium extractants, plant-available K, alfalfa


2018 ◽  
Vol 10 (5) ◽  
pp. 100
Author(s):  
John S. K. Banda ◽  
Alice M. Mweetwa ◽  
Munsanda Ngulube ◽  
Elijah Phiri

The paper reports findings from an evaluation of the effects of selected chemical and biological properties of soils under maize-cowpea cropping systems in Conservation Agriculture (CA) and their relationship to biological nitrogen fixation capabilities of cowpea. Soils from Kayowozi Agriculture Camp of Chipata District of Zambia where CA had been practiced for six years were evaluated. Cropping systems studied included conventional tillage (control), maize monocropping (sole maize), maize-cowpea intercrop, maize-cowpea rotation: maize phase and maize-cowpea: cowpea phase. Standard laboratory procedures were used to determine the changes in the selected soil properties as a result of these cropping sequences under CA. The study showed that maize- cowpea intercrop and rotation-maize phase under conservation agriculture could result in a significant increase in soil organic carbon, total nitrogen and exchangeable calcium after six years of practice. This increase can be associated with the amount and type of residue retained and the contribution of biologically fixed nitrogen from the cowpea. Having cowpea as the immediate previous crop in sequence can result in a depression of soil pH. Soil pH, total nitrogen, available phosphorus and exchangeable calcium in maize-cowpea cropping sequences can influence the amount of biologically fixed nitrogen. Changes in soil activity and microbial biomass might need more than six years to be apparent. The sequencing pattern of crops in a rotation, the choices and characteristics of crops, and the length of time of practice, all play an important role in determining interactions and processes leading to changes in soil properties and crop performance over time.


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